We love using Skype for international calls, but I don't see how it could replace your home phone. It would be a pain to receive phone calls on the computer. If you're cooking or relaxing in bed, you don't want to get up. And while sometimes I make phone calls from using Skype (within the U.S.), I'll stop as soon as it costs me something.
For international calls, though, we like it better. Everyone can participate in the phone call at the same time. It's more like a family reunion.
Dan